Marking out Roman Mosaic Geometric Patterns

In the Geometric manual, ‘Patterns, a fundamental principle’  I write of working out the measurements for your mosaic in terms of the tesserae size and not inches of centimetres. This way you look at the mosaic in terms of what it is made of and not just trying to make it fit into the space you want it to.

On the last Advanced course I was very fortunate to have as my student, Stephen Fitts, a tiler of 40 years experience. We discussed many of the theories of how the Roman mosaicists may have worked and one thing that he brought up was the point that you can mark out an entire floor without using any form of measuring tape or ruler. Nothing that is marked with standard measurements in inches or centimetres.

Briefly, how it is done is like this. Take the measurement of one tesserae as your most basic unit. In the band with 3 colours and a line of black bordering each side you have another unit of measurement which is 5 tesserae, and so on for all the shapes in your mosaic.

Instead of you working what these are in terms of centimetres/inches you just mark these out on a length of wood, almost like a staff. They can be of varying lengths but if you’re working in the same tesserae size then all the measurements you mark on there remain constant.

Image you’re marking out something like the 2 strand guilloche, below;

On your staff you have marks which would be the width of this pattern (the area top to bottom), the space between each centre point, (the white tesserae in the middle) and also the width of 5 tesserae. You can mark out the length of the border and width of the whole border and also using a piece of string and charcoal or a large set of dividers with a spike at each end to score the lines you can draw a circle to mark out the loops.

You would have any number of staffs, some with general markings plus some which are marked up for specific geometric patterns.

This is a large subject to cover but over the next month I will go over it in more detail and I’ll also show how a large mosaic (4m x 8m) can be accurately marked out without using any of the measuring instruments which we have available today.

Roman mosaic tools?

Roman mosaic tools?

Here’s another link to a website which has images of stone working tools, the set of hammers looking exactly the same as the hammers we use now. Unfortunately it’s in Italian and the Google translation leaves something to be desired so I can’t quite figure out whether they are from a Medievil workshop or from an ancient site.

http://www.romanoimpero.com/2012/05/devastazione-roma-marmorari-66.html

Rome Wasn’t Built in a Day, Villa Reconstruction

This post relates to the mosaic made for the Roman Villa reconstruction at Wroxeter. Details of the programme are currently on the Channel 4 website here  http://www.channel4.com/programmes/rome-wasnt-built-in-a-day

If you’re not in the UK you can’t watch the programmes but you can go on the virtual tour. To see the mosaic click on ‘Triclineum’, click and hold and then move your mouse to move the picture round and you will be able to see some of the mosaic.

Rome Wasn’t Built in a Day – The Mosaic

What did I think of it? First things first, I think the guy who was responsible; Kevin was set up to fail. I would have been very surprised if he had pulled it off. Mosaic work, Roman or Contemporary is easy to learn, it’s not rocket science. You draw a line, put your adhesive on the line then put your tiles tesserae (tiles) on the adhesive. That’s it, how good you get is down to how many you do. To make a Roman mosaic floor of that size takes careful planning and experience, having someone looking over his shoulder would have made all the difference.

When you have a project that makes much of its authenticity and use of original methods and materials then it must expect to be reviewed by others with experience in those fields. You only need to look at the comments on the website to see how people take at face value what they see in these programmes.  Here then are the main points that I feel need highlighting, (with the caveat that we only see the final edited programme and I am looking at images from the programme and from the website, I’ve not been there in person);

1. The materials, coloured clay was used for parts of mosaics in Britain, notably the red is cut up roof tile, pottery pieces. They made extensive use of local stone. Clay is not strong enough as a floor surface and if you colour it the colour needs to be part of the entire piece. Just colouring the outside doesn’t work as this will be worn away. He did though do very well in producing that amount of tesserae for the mosaic.
2. The method, there is absolutely no hard evidence to say they prefabricated the mosaics on cloth. Cloth at that time would have been very valuable and not something to use for this sort of thing. We do have hard evidence that they scored marks/guidelines in the surface of the floor and set the tesserae direct.
3. The Rules, andamento, whatever you want to call it. The Romans used a set of rules in every mosaic they made, that’s the reason you see a line of the background colour tesserae around every figure. This borderline rule is also seen in geometric mosaics. In parts of this mosaic you can see some attempt at a borderline but mostly it’s not apparent. These rules are why you can criticise a Roman mosaic but not contemporary mosaics. In modern works there are no rules.
4. The central motif, a bull’s head had the background made using what looked to be white Carrara marble. This is a pure white marble (it appears slightly grey on the programme which is how it appears when it is wet). When we talk of a white background we mean off white. Pure white is very rarely seen in a Roman mosaic as it is a very ‘flat’ colour. The stone of choice is something like Botticino, a marble with a very slight shade variance. It is this variance which gives the impression of depth.

It’s a real shame this ended up like this. I do not hold, as has been said that there are examples of Roman mosaics that are this rough. If there are I’ve not seen them. As I mentioned right at the start the chap who landed this job did not appear to have any real professional back up so you cannot hold him responsible. You only have to look at the example of the timber framing, the carpenter had problems with it and rightly or wrongly (in my opinion wrongly) he was removed from the project. And then they got in a professional timber framing company to do the rest. If they had had a professional guiding him for that part of the project maybe they would have pointed out earlier that it’s a job that is not possible for one man using hand tools.

It’s not being precious about this work but I think we owe it to the original craftsmen to make a bit more effort if we’re going to make these reconstructions.

Copies or original art work?

‘Do not seek to follow in the footsteps of the men of old; seek what they sought.’

Matsuo Basho 1644 – 1694

 

A perfect quote for this type of work, however hard we try we will never be able to make an exact replica of an original Roman mosaic. What we should do is understand how they worked, then through our own experience understand why they worked the way they did. Can you look at an open space and see in your minds eye a mosaic floor in that space? Can you see the patterns, the colours?

Grout Colour

I always use grey grout for the Roman mosaics, never white or Ivory. These lighter colours tend to ‘separate’ the tesserae (tiles) whereas the grey pulls them together allowing the focus to be on the pattern.

Another thing I do is to use the adhesive as a grout. Grout is, essentially a fine powder grout. When you wipe off the excess it should remian fairly level with the top of the tiles. Use the courser adhesive mix and when you clean it off it will remove more of the cement leaving a more ‘worn’ look.

Learning the Rules of Roman Mosaics

Every piece of stone (tesserae) used in creating the patterns and figural images in Roman mosaics were laid according to a set of rules (sometimes referred to as Andamento). To make a copy of a Roman mosaic you need to know these 9 rules and how they were applied. The best way is to learn in 3 stages.

1. Learn the Rules and their use in a ‘perfect’ mosaic. We are fortunate now that just by looking in books or on the internet we can learn how the Rules were used by seeing mosaics from all over the Roman Empire. At the time they were laid 2,000 years ago the craftsmen learnt just by an oral transmission, learning on the job so to speak. It is doubtful they had any manuals to work from so they would have learnt from their head/master mosaicist and the teaching would have been only as good as his work. So, from this we are able to learn almost a gold standard of the Rules, how they are applied in the best of work.

2. Learn the exceptions to the rules, a good example of this is not using triangles to disrupt a curved line but using keystone shaped tesserae instead. If we look at the standard double strand/plait Guilloche pattern, you can see  keystone shapes used in the coloured lines  but  triangles are used in the inner black lines. This is because the angle of the black line is too acute and you would end up having to cut too many keystones.

In the original mosaics you’ll see that very few keystone cuts are used. When you use tesserae that are all slightly irregular you can just tease out the gaps to allow you to follow the curve without any other cutting.

3.Study the different standards of work, as with anything there will always be some workers you’d be glad to do your mosaic and some you wouldn’t, unless that was all you could afford. So when you look at original mosaics, see the Rules used, see the exceptions then try to determine the quality of the work. Some patterns are slightly off; some figures might be out of proportion (some of this may be stylistic but that is a different subject) and look at the backgrounds. The mosaicist could have done the figures then left his assistants to fill in the background, working at different angles you can get quite a disruptive effect. Normally when setting background you work on horizontal lines so look at a large background area and you can get an idea of which way the mosaicists wwere sitting as they worked.

Learn the Rules; apply them in your own work and whenever you get an opportunity look at the original mosaics to develop your eye.

Lawrence Payne

www.romanmosaicworkshops.com

What makes a Roman floor mosaic? Why is it different to Contemporary work?

The following is my professional opinion, and is what I work to here.
If you look at a mosaic which is labelled as ‘Roman’ what is it about it that makes this distinction? Well there are 2 stages to this;
1. The use of the Rules
2. The use of cut stone tesserae of slightly differing sizes.
1. The use of the Rules or Andamento, these govern the way in which the patterns and forms are set. The borderline of background tesserae used around figures is the most easily spotted. Without the application of this rule to a figural mosaic it will become a piece of modern work (and I don’t know of any figure mosaic from Antiquity which was set without this).
Take this to its extreme and you can have 2 people copying a Roman pattern. A 10 year old child using pieces of coloured card next to an artist creating a mosaic using stone tiles (tesserae) and Pozzolan (Roman cement) but without applying any of the Rules and the child would have the most authentic Roman mosaic.
2. Once you are applying the Rules the next stage it to use stone. Some floor mosaics had pieces of coloured glass in them, some (particularly in Roman Britain) utilised cut up roof tile or pottery for the red colours but 99% of the material used was natural stone.
There is a skill to matching colours particularly in figural/portrait work but the main skill you need to acquire is to be able to with tesserae that may be all of the same average size but every piece is slightly different in its overall size, (please refer to my article on backgrounds).
So, 2 areas, the first is you need to apply the Rules in setting your mosaic, next you need to be able to use individually cut tesserae. Using wholly machine cut stone cubes (i.e. every face is 10mm x 10mm) is a different thing all together and it is very difficult to lose the straight edges.

Lawrence Payne

www.romanmosaicworkshops.com

Basic Colours in Roman Mosaics

If you’re making copies of Roman mosaics or producing contemporary ‘inspired by’ mosaics then you need to start with a basic colour palette. Here is a list of the main colours you need to start with. I’ve included the best stone colours to help you, (when I talk of colours I tend to be refering to the various shades of a colour as with stone it is not that often that you get a ‘pure’ colour except with black or white).

You need Black, White, Red and Yellow. These give you enough to start with for your geometric patterns etc. Next add Dark Red and Green. After this look at your specific piece you want to create and you’ll be looking at adding brown and various shades of red/pink which gives you the range to start on figured and portrait work.

White - Firstly I don’t mean white! The background stone you tend to see in Roman mosaics is an off-white, almost a very light beige colour. Pure white is very rarely used in a Roman mosaic except for small areas. The reason for this is that white as a background produces a very flat effect. Using off white stone such as Botticino creates more depth as this stone has different shades running through it. Up close it does look like a light beige colour but in the mosaic and seen from 5′ – 6′ away it produces the effect of a white.

Best stone; Botticino (a number of types, go for Bott. Classico for the best), Crema Marfil, Biancone looks like a bright white but is veined and has an almost imperceptible green tinge to it.

Black; Nero Assoluto, Zimbabwe Black (granite), Nero Macquina, Toros Black. The last 2 have white veins and a more ‘dusty’ look to the colour. NB Never be tempted to use slate! I was given some in 15mm x 15mm x 10mm and although it looked fine, just like the Nero it was hell to cut. Slate shears, ie the top layer separates from the bottom. Not fun to cut believe me.

 Red; Light red as in Rojo Alicante. The standard red used in patterns. veined but nice to use.

Yellow;  Giallo Atlantide, Sienna. Yellow is a problem, the most reliable for a good shade is the Giallo Atlantide. There is a good yellow in Travertine Giallo but Travertine is rock formed by the residue from geysers, millions of years ago. This solidifies with air bubbles hence Trav. has a pitted surface. Too much pitting and it will take up any grout you use which is a shame as it does have a good colour.

 Dark Red; Rosso Laguna, standard for dark red. Not that common as tiles though so be prepared to look around. Cuts ok.

Dark Green; Verde Guatamala, a really beautiful, deep green. Lovely, lovely colour but quite dark. Against black it can merge. There are lighter greens but these can be quite expensive. Unfortunately I don’t have a decent picture of this one.

So, just a quick list. There are many more coloured stones finding their way onto the market now so this list may alter. It really does depend on the quality of the stone, its availability, how it cuts amongst other considerations. 

Lawrence

www.romanmosaicworkshops.com

The Best Way To Cut Irregular Shapes For Your Mosaic

With any mosaic, Roman or Modern it is usual to prepare as much of your tesserae beforehand. That way when you are making the mosaic itself you don’t have to constantly stop to get more material. In this article I’m looking at using marble rods. These are strips of marble roughly 200mm – 300mm in length, 20mm width, 10mm thickness. Using the hammer and hardie you cut the rods into individual tesserae.

 You cut the rods down to your working size say, 10mm cubes. Unless you’re taking too much time with your cutting, the pieces will all end up about 8mm -12mm cubes. Then when you have enough, start work.

As you set the mosaic you cut the other shapes as you need them, the exception being if you need a lot of triangles. If you do need plenty of these then it does help to cut them before. As your work improves, then where you need triangles each time you will leave enough space to accommodate the correct size of triangle.

 I don’t spend too long looking through the already cut material for a tesserae to fit a gap, maybe only 2 -3 pieces before I cut a piece to fit. The process of mosaic is too time consuming to get bogged down in things like that when you have a hammer and hardie with which to create the piece you need. As you get more experienced then you will be able to look at the gap, cut the piece and it will fit on the first or second go.

 Cutting shapes

 Triangles, use the ‘best’ tesserae you have already cut, i.e. the most regular sized cubes. This makes it easier to get 2 good size pieces.

 Half sizes (i.e. 10mm x 5mm x 10mm), as above.

 Keystone, select your cut tesserae which are slightly longer than the rest. Something which is say, width 10mm x length 15mm x depth 10mm. With this longer, more rectangular shape you can cut the triangular section off from each end without ending up with just a triangle.

The principle behind all this is to allow you to work at your best speed.

• Prepare your main tesserae before you start.
• Cut irregular shapes (triangles, half-size, keystone etc) as you go along.
• Develop your cutting skill to be able to cut tesserae to fit irregular gaps assessing the size/shape needed by eye alone.

In an ideal work you’d be working with an assistant sat next to you with a hammer and hardie. You have baskets of prepared tesserae and as you need irregular shapes you just have them cut them for you. That way you don’t have to stop, turn to the side, cut, turn back to the mosaic. You would just focus on the mosaic work itself.

Lawrence Payne

www.romanmosaicworkshops.com

Roman Mosaics – Background Tesserae

This is an area which I’ve not placed as much emphasis on as I should have done. In making copies of Roman mosaics after knowledge of The Rules this is the most important area. If you want to know how good a copy of a Roman mosaic is, look at the background. If the proper attention has been paid to this then the work is complete.

Firstly we need to look at the original mosaics. As we can see from the images below the background is made up of off- white tesserae and they’re not all the same size. The working size for tesserae (tiles) is 8 – 12mm and with all the tesserae being hand cut using a hammer and hardie each piece is very slightly different in size and shape though all those used will fall into the average size.

  The lines of tesserae run on the horizontal, generally you could run a straight line through the centre of the row but you wouldn’t be able to do that along the top or bottom edge of each row.

Here lies the skill, you need to be able set the tesserae allowing for the slight difference in size but keeping all the time to one, single line. If at some point the size of tesserae used are too large or too small then this has an effect not only on that row but also the next row you set.

If you have a row with larger pieces on the left half of the line and you then start to use progressively smaller tesserae ( and I’m talking 2 -3 mm smaller) which is a common mistake, then the next row below it will get halfway across and will reach an area where you’ll need to set much larger tesserae to avoid the lines beginning to slope upwards.

Or  you want to work a little faster so you use tesserae which are just a little too large. This means that the line below either has to have tesserae a lot smaller to stop the line sloping downwards or you allow the line you’re working on to continue to get smaller until it disappears against the larger tesserae above, the last tesserae of this line will be a triangle. The next line below that will be straight but you’ve created a ‘point of focus’ (by the use of the triangle) where one line disappears.

This triangle will creates the point of focus. This one point where the triangle is used will, at some point catch the viewer’s eye. Then, every time they enter the room this point will be the first thing they see.

Another common mistake I see made is when the tesserae are set using pieces that get progressively smaller but longer, i.e. shaped like a brick. A brick wall has a very ‘flat’ look to it and with a Roman mosaic you need to get the impression of depth.

There are a number of other considerations for the background which I will cover in a later article.

The background should be exactly that, background. You shouldn’t notice it but you need to pay attention to it to ensure that you do not create any points of focus. Keep the tesserae within your working size, ensure the gaps remain constant and wherever possible make sure your lines run straight.

Lawrence Payne

www.romanmosaicworkshops.com